U.S. patent number 10,192,915 [Application Number 15/652,759] was granted by the patent office on 2019-01-29 for optical sensor and manufacturing method thereof.
This patent grant is currently assigned to Visera Technologies Company Limited. The grantee listed for this patent is VisEra Technologies Company Limited. Invention is credited to Yueh-Ching Cheng, Wei-Ko Wang, Chia-Hui Wu.
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United States Patent |
10,192,915 |
Wang , et al. |
January 29, 2019 |
Optical sensor and manufacturing method thereof
Abstract
An optical sensor includes a sensing layer, a first shading
filter, a second shading filter, and an alignment mark. The sensing
layer includes an active area, a shading area, and a peripheral
area. The sensing layer includes sensing units located in the
active area. The first shading filter is disposed on the shading
area. The second shading filter is disposed on the first shading
filter. The alignment mark is disposed on the peripheral area. When
a light beam is emitted to the shading area, the second shading
filter is configured to block a first component of the light beam,
and the first shading filter is configured to block a second
component of the light beam.
Inventors: |
Wang; Wei-Ko (Taoyuan,
TW), Cheng; Yueh-Ching (Hsinchu, TW), Wu;
Chia-Hui (Lunbei Township, Yunlin County, TW) |
Applicant: |
Name |
City |
State |
Country |
Type |
VisEra Technologies Company Limited |
Hsin-Chu |
N/A |
TW |
|
|
Assignee: |
Visera Technologies Company
Limited (Hsin-Chu, TW)
|
Family
ID: |
65023520 |
Appl.
No.: |
15/652,759 |
Filed: |
July 18, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
21/68 (20130101); H01L 27/14636 (20130101); G02B
5/22 (20130101); H01L 27/14685 (20130101); G02B
5/201 (20130101); H01L 23/544 (20130101); H01L
27/14623 (20130101); H01L 27/14645 (20130101); H01L
27/14621 (20130101); H01L 2223/54473 (20130101); H01L
2223/54426 (20130101); H01L 27/1464 (20130101); G02B
5/003 (20130101) |
Current International
Class: |
H01L
27/00 (20060101); H01L 27/146 (20060101); H01L
21/68 (20060101); H01L 23/544 (20060101); G02B
5/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2008053713 |
|
Mar 2008 |
|
JP |
|
2010062417 |
|
Mar 2010 |
|
JP |
|
2011159706 |
|
Aug 2011 |
|
JP |
|
Primary Examiner: Harriston; William
Attorney, Agent or Firm: Muncy, Geissler, Olds & Lowe,
P.C.
Claims
What is claimed is:
1. An optical sensor, comprising: a sensing layer comprising an
active area, a shading area around the active area, and a
peripheral area around the shading area; a first shading filter
disposed on the shading area; and a second shading filter disposed
on the first shading filter, wherein one of the first shading
filter and the second shading filter extends from the shading area
and is disposed over the active area, and wherein when a light beam
is emitted to the shading area, the second shading filter is
configured to block a first component of the light beam, and the
first shading filter is configured to block a second component of
the light beam.
2. The optical sensor as claimed in claim 1, wherein the first
shading filter is distant from the peripheral area.
3. The optical sensor as claimed in claim 2, wherein the second
shading filter is further disposed on the peripheral area.
4. The optical sensor as claimed in claim 1, further comprising a
conductive pad disposed on the peripheral area, and an alignment
mark disposed on the peripheral area and distant from the
conductive pad.
5. The optical sensor as claimed in claim 1, wherein the first
shading filter and the second shading filter are distant from the
active area in a stacking direction perpendicular to the sensing
layer.
6. The optical sensor as claimed in claim 1, further comprising a
plurality of color filters disposed on the active area, wherein the
first shading filter is around the color filters.
7. The optical sensor as claimed in claim 6, wherein the first
shading filter is further disposed on the color filters, and the
second shading filter is distant from the color filters.
8. The optical sensor as claimed in claim 6, wherein the second
shading filter is further disposed on the color filters, and the
first shading filter is distant from the color filters.
9. The optical sensor as claimed in claim 1, wherein the first
component of the light beam blocked by the second shading filter
comprises an infrared spectrum, and the second component of the
light beam blocked by the first shading filter comprises a visible
spectrum and an ultraviolet spectrum.
10. The optical sensor as claimed in claim 1, wherein the first
component of the light beam blocked by the second shading filter
comprises a visible spectrum and an ultraviolet spectrum, and the
second component of the light beam blocked by the first shading
filter comprises a visible spectrum and an infrared spectrum.
11. The optical sensor as claimed in claim 1, wherein the first
shading filter is a short-pass filter, and the second shading
filter is a long-pass filter.
12. The optical sensor as claimed in claim 1, wherein the first
shading filter is a long-pass filter, and the second shading filter
is a short-pass filter.
13. The optical sensor as claimed in claim 1, wherein the first
shading filter is configured to block wavelengths of the light beam
longer than a first wavelength, the second shading filter is
configured to block wavelengths of the light beam shorter than a
second wavelength, and the first wavelength is shorter than the
second wavelength.
14. The optical sensor as claimed in claim 1, wherein the first
shading filter is configured to block wavelengths of the light beam
shorter than a second wavelength, the second shading filter is
configured to block wavelengths of the light beam longer than a
first wavelength, and the first wavelength is shorter than the
second wavelength.
15. The optical sensor as claimed in claim 1, wherein the first
shading filter is made of a photoresist or multilayer coating, and
the second shading filter is made of a photoresist.
16. A manufacturing method of an optical sensor, comprising:
forming a first shading filter on an active area, a shading area
and a peripheral area of a sensing layer, wherein the shading area
is around the active area, and the peripheral area is around the
shading area, and an alignment mark is located on the peripheral
area; performing an alignment process on the alignment mark by an
alignment device; removing the first shading filter over the
peripheral area; and forming a second shading filter on the shading
area, wherein a light beam is emitted to the shading area, the
second shading filter is configured to block a first component of
the light beam, and the first shading filter is configured to block
a second component of the light beam.
17. The manufacturing method as claimed in claim 16, further
comprising forming color filters on the sensing layer, wherein the
first shading filter is around the color filters.
18. The manufacturing method as claimed in claim 16, further
comprising performing a second alignment process on the alignment
mark by a second alignment device.
19. The manufacturing method as claimed in claim 16, further
comprising removing the second shading filter over the peripheral
area.
20. The manufacturing method as claimed in claim 16, wherein the
first shading filter is made of a photoresist or multilayer
coating, and the second shading filter is made of a photoresist.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
The present disclosure relates to an optical sensor, and in
particular to an optical sensor with shading filters.
Description of the Related Art
An optical sensor, such as a spectrum sensor or an image sensor, is
configured to detect light or capture an image from an object. In
general, the optical sensor utilizes photodiodes in a sensing layer
to sense light, and covert the light into electrical signals.
The optical sensor is generally mounted in an electrical device,
such as a spectrum meter or a camera. When a light beam is emitted
into the electrical device, the light beam may be reflected by the
housing or a metal element in the electrical device to some
photodiodes. The reflected light beams falling on the photodiodes
are represented as noises, which causes the quality of the
detection or the image to decrease, and thus shall be reduced. In
the conventional art, a block material disposed on the sensing
layer is utilized to block the reflected light beam to fall on the
photodiodes.
However, when the block material is formed on the sensing layer,
the alignment marks on the sensing layer are covered by the block
material. This causes an alignment device to not detect the
alignment marks, and thus the subsequence processes cannot be
performed. The conventional practice is to manually remove the
block material over the alignment marks. However, this causes the
manufacturing time of the optical sensor to be greatly increased.
Consequently, it is desirable to provide a solution for improving
the manufacturing time of the optical sensor.
BRIEF SUMMARY OF THE INVENTION
The present disclosure provides an optical sensor and the
manufacturing method thereof for decreasing the manufacturing time
of the optical sensor.
The present disclosure provides an optical sensor including a
sensing layer, a first shading filter, and a second shading filter.
The sensing layer includes an active area, a shading area around
the active area, and a peripheral area around the shading area. The
first shading filter is disposed on the shading area. The second
shading filter is disposed on the first shading filter. When a
light beam is emitted to the shading area, the second shading
filter is configured to block a first component of the light beam,
and the first shading filter is configured to block a second
component of the light beam.
In some embodiments, the first shading filter is distant from the
peripheral area. The second shading filter is further disposed on
the peripheral area. The optical sensor further includes a
conductive pad disposed on the peripheral area, and an alignment
mark disposed on the peripheral area and distant from the
conductive pad.
In some embodiments, the first shading filter and the second
shading filter are distant from the active area in a stacking
direction perpendicular to the sensing layer.
In some embodiments, the optical sensor further includes color
filters disposed on the active area. The first shading filter is
around the color filters. The first shading filter is further
disposed on the color filters, and the second shading filter is
distant from the color filters. In some embodiments, the second
shading filter is further disposed on the color filters, and the
first shading filter is distant from the color filters.
In some embodiments, the first component of the light beam blocked
by the second shading filter comprises an infrared component, and
the second component of the light beam blocked by the first shading
filter comprises a visible component and an ultraviolet
component.
In some embodiments, the first component of the light beam blocked
by the second shading filter comprises a visible component and an
ultraviolet component, and the second component of the light beam
blocked by the first shading filter comprises a visible component
and an infrared component.
In some embodiments, the first shading filter is a short-pass
filter, and the second shading filter is a long-pass filter. In
some embodiments, the first shading filter is a long-pass filter,
and the second shading filter is a short-pass filter.
In some embodiments, the first shading filter is configured to
block wavelengths of the light beam longer than a first wavelength,
the second shading filter is configured to block wavelengths of the
light beam shorter than a second wavelength, and the first
wavelength is shorter than the second wavelength.
In some embodiments, the first shading filter is configured to
block wavelengths of the light beam shorter than a second
wavelength, the second shading filter is configured to block
wavelengths of the light beam longer than a first wavelength, and
the first wavelength is shorter than the second wavelength.
In some embodiments, the first shading filter is made of a
photoresist or multilayer coating, and the second shading filter is
made of a photoresist.
The present disclosure provides a manufacturing method of an
optical sensor including forming a first shading filter on an
active area, a shading area and a peripheral area of a sensing
layer, wherein the shading area is around the active area, and the
peripheral area is around the shading area, and an alignment mark
is located on the peripheral area; and performing an alignment
process on the alignment mark by an alignment device. The
manufacturing method further includes removing the first shading
filter over the peripheral area; and forming a second shading
filter on the shading area. The light beam is emitted to the
shading area, the second shading filter is configured to block a
first component of the light beam, and the first shading filter is
configured to block a second component of the light beam.
In some embodiments, the manufacturing method of the optical sensor
further includes forming color filters on the sensing layer. The
first shading filter is around the color filters.
In some embodiments, the manufacturing method of the optical sensor
further includes performing a second alignment process on the
alignment mark by a second alignment device, and removing the
second shading filter over the peripheral area.
In conclusion, the optical sensor utilizes the first shading filter
and the second shading filter to replace the block material in the
conventional art. Therefore, the first shading filter above the
alignment mark does not need to be manually removed during the
manufacturing process of the optical sensor, and thus the
manufacturing time of the optical sensor is decreased.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood by reading the
subsequent detailed description and examples with references made
to the accompanying drawings, wherein:
FIG. 1 is a top view of an optical sensor in accordance with some
embodiments of the present disclosure.
FIG. 2 is a cross-sectional view of the optical sensor in
accordance with some embodiments of the present disclosure.
FIG. 3 shows transmittance vs. wavelength diagrams of the first
shading filter and the second shading filter in accordance with
some embodiments of the present disclosure.
FIG. 4 is a cross-sectional view of the optical sensor in
accordance with some embodiments of the present disclosure.
FIG. 5 is a flow chart of a manufacturing method of an optical
sensor in accordance with some embodiments of the present
disclosure.
FIGS. 6A, 6B and 6C are schematic views of the manufacturing method
of an optical sensor during intermediate stages.
DETAILED DESCRIPTION OF THE INVENTION
The following disclosure provides many different embodiments, or
examples, for implementing different features of the present
disclosure. Specific examples of components and arrangements are
described below to simplify the present disclosure. For example,
the formation of a first feature over or on a second feature in the
description that follows may include embodiments in which the first
and second features are formed in direct contact, and may also
include embodiments in which additional features may be formed
between the first and second features, such that the first and
second features may not be in direct contact.
In addition, the present disclosure may repeat reference numerals
and/or letters in the various examples. This repetition is for the
purpose of simplicity and clarity and does not in itself dictate a
relationship between the various embodiments and/or configurations
discussed. Furthermore, the shape, size, and thickness in the
drawings may not be drawn to scale, or the drawings may be
otherwise simplified for clarity of discussion, as they are
intended merely for illustration.
It should be understood that additional operations can be provided
before, during, and after the method, and some of the operations
described can be replaced or eliminated for other embodiments of
the method.
FIG. 1 is a top view of an optical sensor 1 in accordance with some
embodiments of the present disclosure. FIG. 2 is a cross-sectional
view of the optical sensor 1 in accordance with some embodiments of
the present disclosure. The optical sensor 1 is configured to sense
light beams, and covert the light beams into electrical
signals.
In some embodiments, the optical sensor 1 is a CMOS (Complementary
Metal-Oxide-Semiconductor) sensor. In some embodiments, the optical
sensor 1 is a BSI (backside illumination) CMOS sensor. In some
embodiments, the optical sensor 1 is an image sensor configured to
capture an image. The image sensor can be applied to an imaging
apparatus, such as a digital camera.
In some embodiments, the optical sensor 1 is a spectrum sensor
configured to detect the spectrum of an object. The spectrum sensor
can be applied to a spectrum meter.
The optical sensor 1 includes a sensing layer 10, alignment marks
20, conductive pads 30, color filters 40, a first shading filter
50, and a second shading filter 60. The sensing layer 10 extends
along a reference plane P1. The sensing layer 10 is configured to
detect incident light beams according to the light beams falling on
the sensing layer 10.
The sensing layer 10 is defined as an active area Z1, a shading
area Z2, and a peripheral area Z3. The active area Z1, the shading
area Z2, and the peripheral area Z3 are located at the reference
plane P1. In some embodiments, the active area Z1 is located at the
center of the sensing layer 10, and located between the top surface
13 and the bottom surface 14.
The shading area Z2 is a ring-like shape, and is around the active
area Z1. The shading area Z2 is located between the active area Z1
and the peripheral area Z3, and between the top surface 13 and the
bottom surface 14. The peripheral area Z3 is a ring-like shape, and
is around the shading area Z2. The peripheral area Z3 is located at
the edges of the sensing layer 10, and located between the top
surface 13 and the bottom surface 14.
The sensing layer 10 may include all of the following elements, but
the sensing layer 10 does not necessarily include all of the
following elements, as long as the object of the sensing layer 10
is achieved. The sensing layer 10 includes a substrate 11 and
sensing units 12. In some embodiments, the sensing layer 10 further
includes other components or layers (not shown in figures), such as
electrical circuits underneath of the sensing units 12 and a
passivation layer configured to protect the electrical
circuits.
The sensing units 12 are disposed in the substrate 11, and arranged
in an array at the reference plane P1. In this embodiment, the
sensing units 12 are located in the active area Z1 and the shading
area Z2, but are not located in the peripheral area Z3. In some
embodiment, the sensing units 12 are located in the active area Z1,
but are not located in the shading area Z2 and the peripheral area
Z3.
In some embodiments, the sensing units 12 are photodiodes. Each of
the sensing units 12 is configured to sense light beams and
generate electrical signals according to the intensity of the light
beams falling thereon. In some embodiments, an image can be
generated according to the electrical signals by a process chip
(not shown in figures).
The alignment mark 20 is used for an alignment process. The
alignment marks 20 is a cross shape, but the shapes of the
alignment marks 20 are various. The alignment marks 20 are disposed
on the substrate 11 and the peripheral area Z3. The alignment marks
20 are exposed from the top surface 13, and may not protrude over
the top surface 13. In some embodiments, the alignment marks 20 are
not disposed on the active area Z1 and the shading area Z2.
The conductive pads 30 are disposed on the substrate 11 and the
peripheral area Z3. The conductive pads 30 are disposed on and
connected to the top surface 13. In some embodiments, the
conductive pads 30 are exposed from the top surface 13, and may not
protrude over the top surface 13. In some embodiments, the
conductive pads 30 are not disposed on the active area Z1 and the
shading area Z2.
The conductive pads 30 are electrically connected to the sensing
units 12. In some embodiments, the conductive pads 30 are
configured to be connected to wires (not shown in figures). The
conductive pads 30 are connected to the process chip with the
wires. In other words, the sensing units 12 are electrically
connected to the process chip via the conductive pads 30.
The color filters 40 are disposed on the active area Z1 of the
sensing layer 10. Each of the color filters 40 is aligned to one of
the sensing units 12 in a stacking direction D1. The stacking
direction D1 is perpendicular to the sensing layer 10 and the
reference plane P1. The color filters 40 are arranged in an array
on a plane parallel to the reference plane P1.
Each of the color filters 40 allows a predetermined range of
wavelengths of a light beam to pass through. In some embodiments,
color filters 40 include red color filters, green color filters,
and blue color filters. For example, the red color filters allow
wavelengths of a light beam in a range from 620 nm to 750 nm (red
light) to pass to the sensing units 12. The green color filters
allow wavelengths of a light beam in a range from 495 nm to 570 nm
(green light) to pass to the sensing units 12. The blue color
filters allow wavelengths of a light beam in a range from 476 nm to
495 nm (blue light) to pass to the sensing units 12.
The first shading filter 50 is disposed on the sensing layer 10 and
the color filter 40. In some embodiments, the first shading filter
50 is not disposed on the peripheral area Z3.
As shown in FIGS. 1 and 2, the first shading filter 50 includes a
lower portion 51 and an upper portion 52. The lower portion 51 is
disposed on the shading area Z2. The lower portion 51 is connected
to the sensing layer 10 and the side walls of the color filters 40.
The lower portion 51 is around the color filters 40. In the other
words, the lower portion 51 is a ring-like shape. In some
embodiments, the height of the lower portion 51 relative to the
sensing layer 10 is equal to the height of the color filters 40
relative to the sensing layer 10.
The upper portion 52 is disposed on the lower portion 51 and the
color filters 40. In other words, the upper portion 52 is located
over the active area Z1 and the shading area Z2. In some
embodiments, the upper portion 52 is not disposed on the color
filters 40, and is not located over the active area Z1.
In some embodiments, the first shading filter 50 is a short-pass
filter. In some embodiments, the first shading filter 50 is made of
a photoresist or multilayer coating. The first shading filter 50 is
configured to block components (remained components) of the light
beam emitted to the shading area Z2. The components of the light
beam blocked by the first shading filter 50 include an infrared
spectrum.
The first shading filter 50 is configured to block wavelengths of a
light beam longer than a specific wavelength (first wavelength). In
some embodiments, the first wavelength is in a range from about 740
nm to 768 nm. In some embodiments, the first wavelength is about
760 nm. In this embodiment, the wavelengths of a light beam blocked
by the first shading filter 50 is defined as the transmittance of
the wavelengths of the light beam passing through the first shading
filter 50 being lower than 20%.
Therefore, an infrared spectrum of a light beam is blocked by the
first shading filter 50. The sensing units 12 under the color
filter 40 may not receive the infrared spectrum, and thus the
quality of the image made by the optical sensor 1 is improved.
The second shading filter 60 is disposed on the first shading
filter 50, and located over the shading area Z2. The second shading
filter 60 is not disposed on the peripheral area Z3 and the active
area Z1. In other words, the second shading filter 60 is a
ring-like shape. In some embodiments, the second shading filter 60
is further disposed on the peripheral area Z3.
In some embodiments, the second shading filter 60 is not disposed
on the first shading filter 50 (or the color filters 40) above the
active area Z1. The first shading filter 50 and the second shading
filter 60 are not disposed on the active area Z1 in the stacking
direction D1 at the same time.
In some embodiments, the second shading filter 60 is disposed on
the color filters 40 above the active area Z1 when the first
shading filter 50 is not disposed on the color filters 40 above the
active area Z1.
FIG. 3 shows transmittance vs. wavelength diagrams of the first
shading filter 50 and the second shading filter 60 in accordance
with some embodiments of the present disclosure. In some
embodiments, the second shading filter 60 is a long-pass filter. In
some embodiments, the second shading filter 60 is made of a
photoresist. The second shading filter 60 is configured to block
some components of the light beam. In some embodiments, the
components of the light beam blocked by the second shading filter
60 include a visible spectrum and an ultraviolet spectrum.
The second shading filter 60 is configured to block wavelengths of
a light beam shorter than a specific wavelength (second
wavelength). In this embodiment, the wavelengths of a light beam
blocked by the second shading filter 60 is defined as the
transmittance of the wavelengths of the light beam passing through
the second shading filter 60 being lower than 20%.
In some embodiments, the second wavelength is in a range from about
772 nm to 800 nm. In some embodiments, the second wavelength is
about 780 nm. The first wavelength is shorter than the second
wavelength.
As shown in FIGS. 2 and 3, the second shading filter 60 is disposed
on the first shading filter 50. The first shading filter 50 is
configured to block wavelengths of a light beam longer than a first
wavelength, the second shading filter 60 is configured to block
wavelengths of the light beam shorter than a second wavelength, and
the first wavelength is shorter than the second wavelength.
When a light beam (such as a white light beam or sunlight) passes
through the second shading filter 60 and the first shading filter
50, all of the wavelengths of the light beam are substantially
blocked by the second shading filter 60 and the first shading
filter 50. In other words, the second shading filter 60 is
configured to block components of the light beam, and the first
shading filter 50 is configured to block remained components of the
light beam. Therefore, all components of the light beam are
substantially blocked by the second shading filter 60 and the first
shading filter 50.
Accordingly, the second shading filter 60 and the first shading
filter 50 above the shading area Z2 prevent a light beam from
falling on the shading area Z2 of the sensing layer 10. The second
shading filter 60 and the first shading filter 50 above the shading
area Z2 are functioned as the black material in the conventional
art.
FIG. 4 is a cross-sectional view of the optical sensor 1 in
accordance with some embodiments of the present disclosure. The
first shading filter 50 is disposed on the shading area Z2. The
first shading filter 50 is connected to the sensing layer 10 and
the side walls of the color filters 40. The first shading filter 50
is around the color filters 40. In the other words, the first
shading filter 50 is a ring-like shape.
In some embodiments, the first shading filter 50 is not disposed on
the peripheral area Z3 and the active area Z1. In some embodiments,
the height of the first shading filter 50 relative to the sensing
layer 10 is equal to the height of the color filters 40 relative to
the sensing layer 10.
In some embodiments, the first shading filter 50 is a long-pass
filter. The first shading filter 50 is configured to block some
components (remained components) of the light beam. In some
embodiments, the components of the light beam blocked by the first
shading filter 50 include a visible spectrum and an ultraviolet
spectrum. The first shading filter 50 is configured to block
wavelengths of a light beam shorter than a specific wavelength
(second wavelength).
The second shading filter 60 is disposed on the first shading
filter 50, and located over the shading area Z2. The second shading
filter 60 is also disposed on the color filters 40, and located
over the active area Z1. In some embodiments, the second shading
filter 60 is not disposed on the color filters 40, and is not
located over the active area Z1.
In some embodiments, the second shading filter 60 is a short-pass
filter. The component of the light beam blocked by the second
shading filter 60 includes an infrared spectrum. The second shading
filter 60 is configured to block wavelengths of a light beam longer
than a specific wavelength (first wavelength). Therefore, an
infrared spectrum of a light beam is blocked by the second shading
filter 60. The sensing units 12 under the color filter 40 may not
receive the infrared spectrum, and thus the quality of the image
made by the optical sensor 1 is improved.
FIG. 5 is a flow chart of a manufacturing method of an optical
sensor 1 in accordance with some embodiments of the present
disclosure. FIGS. 6A, 6B and 6C are a schematic view of the
manufacturing method of the optical sensor 1 during intermediate
stages. In step S101, the color filters 40 are formed on the active
area Z1 of the sensing layer 10. Afterwards, the first shading
filter 50 is formed on the sensing layer 10 and the color filters
40 as shown in FIG. 6A. In other words, the first shading filter 50
is formed on the active area Z1, the shading area Z2 and the
peripheral area Z3 of the sensing layer 10, and covers the
alignment mark 20 and the conductive pad 30.
In this embodiment, the first shading filter 50 is made of a
photoresist. In some embodiments, the first shading filter 50 is
made of a multilayer coating, and the first shading filter 50 is
formed by a lift-off process.
In step S103, an alignment process is performed on the alignment
mark 20 by an alignment device A1 as shown in FIG. 6A. In some
embodiments, the alignment device A1 utilizes a visible light beam
to detect the alignment mark 20 when the first shading filter 50 is
a short-pass filter. In some embodiments, the alignment device A1
utilizes a light beam with a wavelength of about 500 nm to detect
the alignment mark 20.
Therefore, the light beam emitted by the alignment device A1 can
pass through the first shading filter 50 and fall on the alignment
mark 20 when the first shading filter 50 is a short-pass filter.
The alignment process can be appropriately performed without
manually removing the first shading filter 50 above the alignment
mark 20, and thus the manufacturing time of the optical sensor 1 is
decreased.
In some embodiments, the alignment device A1 utilizes an infrared
light beam to detect the alignment mark 20 when the first shading
filter 50 is a long-pass filter. In some embodiments, the alignment
device A1 utilizes a light beam with a wavelength of about 935 nm
to detect the alignment mark 20. Therefore, the light beam emitted
by the alignment device A1 can pass through the first shading
filter 50 and fall on the alignment mark 20 when the first shading
filter 50 is a long-pass filter.
In step S105, a portion of the first shading filter 50 is removed
by semiconductor manufacturing process, such as a lithography
process and/or etching process. The first shading filter 50 over
the peripheral area Z3 is removed as shown in FIGS. 2 and 4. In
some embodiments, the first shading filter 50 over the active area
Z1 is not removed as shown in FIG. 2. In some embodiments, the
first shading filter 50 over the active area Z1 is removed as shown
in FIG. 4.
In step S107, the second shading filter 60 is formed on the sensing
layer 10 and the first shading filter 50 as shown in FIG. 6B. In
other words, the second shading filter 60 is formed on the active
area Z1, the shading area Z2 and the peripheral area Z3 of the
sensing layer 10, and covers the alignment mark 20 and the
conductive pad 30.
In some embodiments, the second shading filter 60 is formed on the
peripheral area Z3, the first shading filter 50 and the color
filters 40 as shown in FIG. 6C.
In step S109, an alignment process is performed on the alignment
mark 20 by an alignment device A2 as shown in FIGS. 6B and 6C.
In some embodiments, the alignment device A2 utilizes an infrared
light beam to detect the alignment mark 20 when the second shading
filter 60 is a long-pass filter as shown in FIG. 6B. In some
embodiments, the alignment device A2 utilizes a light beam with a
wavelength of about 935 nm to detect the alignment mark 20.
Therefore, the light beam emitted by the alignment device A2 can
pass through the second shading filter 60 and fall on the alignment
mark 20. The alignment process can be appropriately performed
without manually removing the second shading filter 60 above the
alignment mark 20.
In some embodiments, the alignment device A2 utilizes a visible
light beam to detect the alignment mark 20 when the second shading
filter 60 is a short-pass filter as shown in FIG. 6C. In some
embodiments, the alignment device A2 utilizes a light beam with a
wavelength of about 500 nm to detect the alignment mark 20.
Therefore, the light beam emitted by the alignment device A2 can
pass through the second shading filter 60 and fall on the alignment
mark 20.
In step S111, a portion of the second shading filter 60 is removed
by a semiconductor manufacturing process, such as a lithography
process and/or etching process. In some embodiments, the second
shading filter 60 over the peripheral area Z3 and the active area
Z1 is removed as shown in FIG. 2. In some embodiments, the second
shading filter 60 over the active area Z1 is not removed as shown
in FIG. 4. In some embodiments, the second shading filter 60 over
the peripheral area Z3 is not removed.
In conclusion, the optical sensor utilizes the first shading filter
and the second shading filter to replace the block material in the
conventional art. Therefore, the first shading filter above the
alignment mark does not need to be manually removed during the
manufacturing process of the optical sensor, and thus the
manufacturing time of the optical sensor is decreased.
The disclosed features may be combined, modified, or replaced in
any suitable manner in one or more disclosed embodiments, but are
not limited to any particular embodiments.
While the invention has been described by way of example and in
terms of preferred embodiment, it is to be understood that the
invention is not limited thereto. On the contrary, it is intended
to cover various modifications and similar arrangements (as would
be apparent to those skilled in the art). Therefore, the scope of
the appended claims should be accorded the broadest interpretation
so as to encompass all such modifications and similar
arrangements.
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